Hi Performance Steel Washers 2

[alwelsh]

I am looking for a source of information, dimensions, material and properties (hardness) and potential suppliers for fasteners, regular flat and lock washers (not helical spring type), for use with SAE Gr8 & A9 (ISO 10.9 &12.9) bolts. Also does anyone have experience with these using Dacromet or geomet coating in an acidic ground water environment.
Thanks in advance

 

[vonlueke]

Only hard washer I've ever found so far, that I remember at the moment, is NAS1149E, stainless steel A-286, standard-diameter flat washer, 1100 MPa (160 ksi). Has very good corrosion resistance. Could not find NAS1149 spec. sheet publicly available on-line.

Be sure to include the trailing "E" in NAS1149E. Otherwise you'll get a completely different, weak material instead of A-286. Cannot comment on the coatings you named.

 

[WKTaylor]

alwelsh...

I agree with Aerospace quality washer [NAS1147E] noted by vonlueke... but there are commercial grades available [hard steel, plated].

Try SAE HS-4000 Fastener Standards Manual [available thru SAE @ web-site!]. Regards, Wil Taylor

 

[butelja]

The standard commercial grade hardened washers used with high strength structural bolting (ASTM A325, A490) are ASTM F436 material. These are available galvanized.

 

[Billybaru]

Butelja is correct. ASTM F436 hardened washers are commonly available in plain, HDG, and zinc-yellow off-the-shelf. Any commercial fastener distributor will either have in stock or can get them quickly. The F436 washers are close dimensionally with the SAE (Narrow) pattern in ANSI B18.22.1. The USS (Wide) pattern in ANSI B18.22.1 is readily available as a hardened washer. If thicker washers are needed, there are private label hardened thick washers, such as the PFC9, available in both patterns at many distributors.